As is known, an air seeder is an agricultural implement that is commonly used to plant a seed crop in a large field. Air seeders typically have centrally located hoppers for seed and fertilizer which distributes the seed or fertilizer via an air stream to individual seed rows. It is convenient to fill and easy to clean out and move. Any crop that can be grown from seeds, which might vary in size from oilseeds to corn, can be sewn by an air seeder.
The seed and fertilizer hoppers are usually carried on a large cart towed behind a tractor or other work vehicle. The air stream is created by a high capacity fan mounted on the cart which blows air through an air dispensing system made up of pipes and/or pneumatic tubes located under the seed and fertilizer tanks. Seed and fertilizer are metered out from the hoppers by a meter wheel that is turning at a rate which is a function of the speed at which the cart is traveling and which is set by the operator for the proper seed rate or seed density. The seeds enter the airstream and follow the pipes or tubes which terminate in the dispenser. Openers pulled through the soil break the soil and create a furrow in which the seeds are placed. The openers may be made of steel in the shape of points, discs, or cultivator shovels. The dispensers are located behind the openers to deposit the seed or fertilizer in the furrow. Once placed in the seed bed, a packer wheel may be pulled over the furrow to pack the soil on top of the deposited seed to retain moisture near the seed and harrow the furrows so the field is not rough.
A typical air seeder has an agricultural commodity cart (“air cart”) comprising at least one, and commonly two, three or more tanks for carrying various agricultural products like seed and fertilizer. Although not always present, commonly there is a conveyor mounted on the cart for transferring agricultural product (“commodity”) from transport vehicles into the tanks. The conveyor is typically mounted on a pivot mechanism configured to allow it to be moved from a transport position, where the bottom end of the conveyor is raised for transport, to an operating position where the bottom end is lowered to receive a commodity from the transport vehicle. The conveyor may include a hopper at the bottom for receiving the product, a tube with an internal conveyor for moving the product up the tube, and a downspout at the top for discharging the product into each tank. Because an air cart may include multiple tanks having independent openings for receiving product, the tube and downspout may be successively aligned with an opening for each tank to facilitate product flow into the respective tank.
Some conveyors are coupled to the air carts by inner arm and outer arms. Each arm may include an independent actuating cylinder configured to adjust a position of the respective arm relative to the air cart. Unfortunately, coordinating movement of the inner and outer arms to align the downspout with each storage compartment opening may be difficult and time-consuming, thereby increasing the duration associated with loading product into the air cart. Other conveyors are coupled to the air carts by way of a single actuating cylinder and a linkage assembly. The hydraulic cylinder is used to position the downspout of the conveyor to align with different openings of the tanks while the linkage assembly is configured to maintain the hopper at a fixed location with respect to the air cart. Although providing more intuitive operation once the hopper is in position under the transport vehicle, this embodiment requires more precise alignment between the air cart and the transport vehicle.